[Test] Mute tests due to KT-56508

compiler/testData/codegen/box/extensionClasses/constructors.kt

@@ -1,6 +1,8 @@
 // !LANGUAGE: +ContextReceivers
 // TARGET_BACKEND: JVM_IR
 // IGNORE_BACKEND_K2: JS_IR
+// IGNORE_BACKEND_K2_LIGHT_TREE: JVM_IR
+//   Reason: KT-56508
 // WITH_STDLIB
 
 class A(val ok: String)
@@ -30,4 +32,4 @@ fun box(): String {
         )
         return if (results.all { it == "OK" }) "OK" else "fail"
     }
-}
+}